Electrophotographic copying machine



Oct. 10, 1967 E. TIGER ETA.

ELECTROPHOTOGRAPHIC COPYING MACHINE Filed NOV. l2, 1964 5 Sheets-Sheet l i INVENTOR. 5272// 7796/" Emsk//ve 6. T9/Wmv? fe/M @l/7 62 @e/ av v/ Y. ATTORNEYS 0d. i0, 167 E. TIGER ETAL ELECTROPHOTOGRAPHIC COPYING MACHINE 5 Sheets-Sheet 2 Filed NOV. l2, 1964 JNVENTOR. f'm 779er Trai/m@ G Cori/Ww? /deffwe Q. @e/ ck 'A TTOR N E YS Oct. 10, 1967 E. TIGER ETAL x 3,345,925

ELECTROPHOTOGRAPHIC COPYING MACHINE Filed Nov. l2, 1964 5 Sheets-Sheet 5 Eggs POWER INVENTOR. Eml/ 7719er* v hse/ne 6T Cof/m an ATTORNEYS United States Patent O 3,345,926 ELECTROPHOTOGRAPHIC COPYING MACHINE Emil Tiger, Highland Park, Erskine G. Corman, Forest Park, and Kenneth R. Reick, Downers Grove, Ill., as-

signors to Formfoto Manufacturing Company, Villa Park, Ill., a corporation of Illinois Filed Nov. 12, 1964, Ser. No. 410,549 13 Claims. (Cl. 95-1.7)

This invention relates to improvements in electrophotographic 4copying machines and more particularly concerns such machines of small, compact generally desk model size and in the present instance of the type employing a liquid toner or developer.

Among the important objects of the present invention is to provide a new and improved electrophotographic copying machine of simplified, compact, rugged and eflicient construction arranged to produce high quality copies automatically and at high speed.

Another object of the invention is to provide new and improved means in a machine of this kind for handling the document t-o be copied.

A further object of the invention is to provide new and improved scanning aperture means for electrophotographic copying machines.

Still another object of the invention is to provide new and improved copy paper feeding means for machines of this character.

Yet another object of the invention is to provide new and improved copy paper feed and control means in an electrophotographic copying machine.

A still further object of the invention is to provide new and improved means for transporting the finished copy.

A yet further object of the invention is to provide a new and improved method of and means for drying the copies after emergence from the liquid toner bath.

It is also an object of the invention to provide new and improved aperture and light shield structure in a machine of this type.

Other objects, features and advantages of the present invention will be readily apparent from the following detailed description of a preferred embodiment thereof taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a vertical longitudinal sectional elevational schematic view through the front portion of a machine embodying features of the invention;

FIGURE 2 is a continuation of FIGURE 1 showing the rear portion of the machine;

FIGURE 2A is an enlarged fragmentary detail view of that portion of FIGURE 2 indicated by the circle IIA;

FIGURE 3 is a sectional elevational detail view taken substantially on the line III- III of FIGURE 2; and

. FIGURE 4 is an electrical diagram of the control circuitry of the machine.

An enclosing cabinet 5 houses a base wall 7, a front wall 8, respective opposite side walls 9, a rear wall and a top wall 11. Within the housing suitable reinforcing and supporting frame structure is provided including' various transverse frame bars 12 the machine and includes In the front upper portion of the housing 5 are provided means for scanning a document original to be copied. For this purpose, the front wall 8 is inset a short distance adjacent to the top of the cabinet and an upwardly facing receiving ledge 13 is provided hand fed into a receiving throat 14 leading to the nip of a driven feed roller 15 and a coacting idler roller 17 by which the document is fed rearwardly through a guide passage between narrowly spaced upper and lower passage plates 18 and 19 which guide the document to the on which documents are.

nip of a second driven feed roller 20 and a coacting idler roller 21 set to divert the infed document diagonally downwardly and rearwardly through a passage defined by an upper guide plate 22 and a closely adjacent spaced lower guide plate 23 leading the advancing document into the nip of a driven feed roller 24 and an idler roller 25 set to bend the leading edge of the document to travel about the driven roller 24 as guided by a semi-cylindrical closely spaced guide bracket 27. Thence, the leading edge of the document passes into the nip of the driven roller 24 and an idler roller 28 by which the document is directed diagonally upwardly and forwardly in reverse to the passage between the plates 22 and 23 and parallel thereto past a scanning aperture 29 defined by a lower document guiding and aperture bracket 30 and an upper spaced document guiding and aperture bracket 31. Cooperative in document guiding relation with the brackets 30 and 31 is a guide and backing plate 32 which extends across the scanning aperture 29 and affords an opaque backing for the document. Improved definition of the documentary material on the scanned face of the document is attained by having the surface of the plate 32 which faces into the aperture 29 of substantially white color as by means of a suitable coating on the surface, where the material of the plate 32 is not naturally of a substantially white color.

Beyond the guide bracket 31, the document is guided into the nip of the driven roller 20 and a cooperating idler roller 33 from which the document is guided into a substantially horizontal planeA forwardly by an upper guide plate 34 and a lower guide plate 35 defining a guide passage therewith leading to the nip of the driven roller 15 and a lower idler feed roller 37 by which the copied document is delivered into and through an exit passage 38 defined between spaced upper and lower plates 39 and 40 and located adjacently below the infeed or entry ledge 13 in the uppermost front portion of the cabinet. Thus, the document makes its entire transport circuit in substantially parallel intravelling and outtravelling legs of a path in which both the intravelling and outtravelling motivation is afforded by the three diiven rollers 15, 20 and 24.

vIllumination of the document as it passes the scanning aperture 29 is effected by means comprising a high intensity tubular lamp 41 mounted within a channelshaped parabolic reflector 42 located `below the horizontal portions of the document transport System and projecting intoV the scanning aperture above `a reflection.

path from the aperture to a scanning mirror 43 mounted on one of the cross bars 12 below and forwardly relativev to the reflector 42.

As indicated schematically by light ray lines in FIG. 1, concentration of scanning illumination of the exposed portion of the document as it passes across the aperture 29 is enhanced by reflecting into the aperture light rays which would otherwise be lost by spreading beyond the effective area of the aperture. For this purpose, reflecting surfaces are provided at least along each longitudinal edge defining the aperture. Such reflecting surfaces are conveniently and efficiently provided by respective flanges 44 and 45 on the brackets 30 and 31, respectively. For maximum light gathering and concentrating effect, the reflecting surfaces of the flanges 44 and 45 are divergently related to one another and to the axis from the ycenter ofthe lamp 41 to the center of the scanning aperture 29. Further, the'planes of the respective reflecting face of the flanges 44 and 45 if projected pass outside of the longitudinal edges of the reflecting surface within the transversely elongated reflector 42. Additionally, of course, the planes of the reflecting surfaces of the flanges 44 and 45 are at a proper angle relative to the lamp 41 to reflect light rays from the lamp into the aperture 29.

Light shielding of the scanning area is afforded by the front wall 8, the document guide passage panels 35 and 40 at the top, by respective opposite vertical side panels 47, a rear shielding panel 48 and a bottom shielding panel 49. At its lower end, the front wall 8 is attached to the front cross bar 12 on which the reectingmirror 43 of the scanning optical system is mounted and which bar is spaced substantially above the bottom wall 7. Attachment of the front end of the bottom shielding panel 49 is also to the front transverse frame bar 12.

Attachment of the upper edge of the rear shielding panel 48 is to the aperture and reflector bracket 30 which, for this purpose, is provided with a longitudinal downwardly and forwardly opening groove 50 alongside the flange 44 and into which the edge portion of the panel 48 is litted. At its lower end, the panel 48 is attached to the adjacent transverse frame bar 12 which is located in rearwardly spaced relation to the mirror 43 and in upwardly spaced relation to the bottom shielding panel 49.

Between the bottom panel 49 and the overlying spaced frame bar 12 is mounted a suitable lens supporting bracket structure carrying image projecting lens means comprising Ian assembly including a barrel 52 and aligned for receiving from the scanning mirror 43- the image of the document passing the illuminated scanning aperture 29 and focusing such image generally rearwardly and in this instance slightly upwardly into an exposure aperture 53 located in about the center of the rear portion of the chamber within the cabinet housing 5. Means providing a projection tunnel from the lens or objective assembly 52 to the exposure aperture 53 comprise a rearward extension of the lower panel 49 and an upper tunnel panel 54 having its forward end attached to the transverse frame bar 12 contiguous to the lens assembly.

Supporting the rear ends of the tunnel-forming extension of the lower panel 49 and of the tunnel panel 54 are transverse parallel, coextensive spaced exposure aperture defining bracket members 55 which are desirably constructed identically as the scanning aperture defining and panel supporting bracket 30, whereby to afford standardization of parts. Each of these brackets may be constructed as an extruded bar, either metallic or nonmetallic as preferred. Similarly as the bracket bar 30, the bracket bars 55 have aperture-defining respective flanges 57 and alongside such flanges respective panel-receiving grooves 58 within which the adjacent edge portions of respectively the tunnel-defining panels 49 and 54y are engaged.

Means are provided for supplying and feeding successive copy sheets 59 to pass through the exposure aperture 53 in synchronized relation with passage of a document to be copied through the scanning aperture 29,'To this end, a copy sheet magazine including a magazine receptacle 60 is mounted in the housing above the document transport assembly and extending rearwardly under the top wall 11 to a suitable position rearwardly above the projection tunnel Iand the exposure aperture 53. Access into the copy `sheet supply magazine is conveniently through a hinged cover 61 forming part of the top wall.

Feeding of successive copy sheets from a stack in the magazine receptacle 60 is effected by means of a frictional feed roller 62 which lies on top of the rear portion of the stack and is carried by one or more arms 63 of a pivotally mounted roller supporting frame pivoted at its rear end portion on a horizontal axis pivot `64. Thereby the feed roller 62 lies in freely descending, downwardly thrusting relation on the copy sheet stack for gravitationally pressing against and feedingly gripping the uppermost of the copy sheets.

Means for driving the feed roller 62 comprise a simple, inexpensive electrical motor 65 conveniently mounted under the rear portion of the top wall 11 and alongside the right-hand inner housing vertical frame panel 47 and having a drive shaft 67. Means for coupling the drive shaft 67 with the feed roller 62 comprise a drive pulley 68 mounted on the drive shaft and having trained thereover a flexible driving element such as an endless driving belt 69 which is also trained over a similar driving pulley (not shown) carried co-rotatively by one end portion of the roller 62 and more particularly its shaft by which the roller is journalled on its pivotal carrying bracket. Since the feed roller 62 is driven counterclockwise as viewed in FIGURE 2, with its direction of rotation thus downwardly and rearwardly, the driving torque thereon supplements gravitational downward thrust of the feed roller 62 for firm positive gripping and feeding of each successive copy sheet. Yet, the feeding thrust is not excessive, so that the topmost sheet can freely slide off of the next succeeding sheet. In addition to stack resistance to feeding of multiple sheets, adjustable side gripping means 70 may be provided to engage the sides of the stack of sheetsv in the magazine.

From the magazine 60, each of the copy sheets 59 is directed into a converging guide throat 71 extending rearwardly and then downwardly to guide the fed copy sheet into a plane past the exposure aperture 53. At the lower end of the guide throat the copy sheet is directed to the nip of a driven feed roller 72 and a coacting idler roller 73 which then assume onward feeding transportation of the copy sheet.

For electrophotographic copying, the copy sheets 59 are of the electrophotographic type such as a paper backing having a photosensitive coating comprising zinc oxide or the like plus a binder. Such material is adapted to take an electrostatic charge on passing through a charging device 74 including corona discharge wires 75 located alongside and across the path of travel of the copy sheet, and preferably on both sides of such path. This corona charging device 74 is located as close as practicable to the downstream side of the feed rollers 72, 73 and adjacent to the upstream side of a set of feed rollers comprising a driven roller 77 and a coacting idler roller 78 to the dielectric nip of which the charged copy sheet is fed from the charging device. Immediately following the feed rollers 78 and 77, the charged copy sheet passes the exposure aperture 53 with the sensitized surface of the sheet exposed to the image projected from the scanned document concurrently passing the scanning aperture 29. Backing the copy sheet across the aperture 53 is a plate 79 cooperating in appropriately spaced relation with the aperture-defining brackets 55 to provide a passage and guide for the sheet. Immediately on leaving the exposure aperture guide passage, the exposed sheet is engaged by a set of dielectric transport rollers comprising a driven roller 80 and a coacting idler roller 81.

Immediately on leaving the transport rollers 80 and 81, the exposed sheet is transported through image developing and fixing means comprising a receptacle 82 in the form of a trough-like tray opening upwardly and having an elevated rear curved lead-in edge 83 adjacent to the discharge side of the rollers 80 and 81. Within the developer tray 82, the copy paper is guided in an arcuate path downwardly and forwardly and then generally upwardly and forwardly and passes through a developer bath 84 comprising a suitable liquid vehicle and toner or developer particles. This developer bath or solution is maintained in constant circulation from a supply tank 85 below the tray 82 and from the bottom of which the solution is pumped by a pump unit 87 through a riser duct 88 into the bottom of the tray and returns through an overow duct 89 leading from the tray into the tank. Driving of the pump unit 87 is by a pump motor 90 which may be conveniently mounted above a top cover 91 for the tank S5 on posts 92 and has a drive shaft 93 extending down into driving relation with the pump unit 87.

On leaving the toner bath 84, the developed copy sheet is directed by the curved guide wall of the tray 82 into the nip of transport and squeeze rollers comprising a driven roller 94 and a coacting idler roller 95 by which the surplus solution is squeezed from the copy sheet and the sheet is transported away from the developer tray. Solution squeezed from the sheet is received in a drip trough 97 under the roller 94 and comprising a forward extension on the tray 82. A drain duct 98 returns collected solution from the trough 97 into the tank 85. Access to the developer tank and tray assembly may be had through the back wall of the housing through a removable panel or door 99.

On leaving the squeezing and transport rollers 94, 95 the still damp and now fully developed copy sheet is propelled generally forwardly and is deflected downwardly and forwardly by the overlying tunnel extension of the shield 49 which is desirably provided with longitudinal downwardly projecting spacer ribs 100 to avoid possible adherence of the damp copy sheet thereto. Underlying the path of movement of the copy sheet as discharged from the rollers 94 and '95 is a downwardly and forwardly extending guide plate 101 providing a discharge chute leading to a receiving area in the lower forward portion of the housing between the bottom Wall 7 and the top side of the chute provided by the downwardly facing wall of the light tunnel, herein the shield panel 49 and readily accessible at the front of the machine below the mirror 43 for removal of the finished copies.

Means are provided for accelerating movement of the dischargeed copy sheets down the ramp into the receiving hopper and for simultaneously drying the damp sheet's. In a highly desirable manner, this is effected by providing an air cushion under the sheets as they travel down the chute or ramp 101 whereby to effect an anti-friction air layer under the sheets to float the sheets into the receiving hopper. For accelerating drying of the sheet such air is desirably heated. Economically, the source of waste heat created by the scanning lamp 41 is utilized for the purpose. Therefore, an air circulation suction port 102 is provided in one of the vertical frame panels 47, herein the one located at the left side of the cabinet adjacent to the reflector trough and of a size to pass a substantial volume of air therethrough from the scanning chamber. Leading from the suction port 102 downwardly and rearwardly between the frame panel 47 and the adjacent side wall 9 is a suction duct 103 extending downwardly and rearwardly and communicating with a horizontal suction tube 104 which opens into the intake of a rotary squirrel cage blower 105 located to discharge toward louvers 107 opening through the lower end portion of the chute plate 101 and through a vertical downward partition extension 108 of the chute plate defining the rear of the receiving hopper area. Through this arrangement, cooling air is circulated through the scanning chamber and over and past the lamp 41 and the reflector 42 as a result of suction developed by the blower 105 and the heated air is blown through the louvers 107 to provide the discharged copy sheet propelling and drying air movement as indicated by the directional arrows in FIG. 2A. After the trailing edge of the copy sheet passes beyond the lower end of the chute plate 101, air blown through the louvers 107 in the plate 101 as well as the air issuing through the louvers 107 in the vertical partition 108 acts on the upper side of the sheet to force it downwardly onto a receiving plate 109. It will be observed that the series of louvers 107 terminates a substantial distance above the innermost end of the receiving plate 109 so that as the rear end of the copy sheet drops below the series of louvers, pressdown action 'of the air pushing through the louvers accelerates piling of the sheet toward the receiving plate. To facilitate removal of copy sheets from the discharge receptacle, a retractable plate structure 110 may be provided.

Driving of the blower 105 as well as all of the several document original and copy sheet transport rollers is effected by a single electrical motor 111 having a drive shaft 112 extending therethrough and on one end portion of which the blower 105 is directly corotatively mounted. The opposite end portion of the shaft 112 is suitably coupled with a suitable speed reducing gear unit 113 supporting the motor and carried by the adjacent side vertiactuator 130 of a normally closed switch Ation of documents to be copied cal frame panel 47. A drive shaft 114 of the reduction gear unit carries corotatively a driving wheel which may comprise a sprocket 115 over which is trained a flexible driving coupling member comprising a chain 117 running drivingly over respective sprocket gears on the several driven transport rollers. At a suitable point, as in the span of the drive chain 117 between the driven rollers 24 and 72, a slack take-up idler 118 is desirably provided. Through this arrangement, all of the driven rollers travel at the same speed in both the document original transport system and the copy sheet transport system.

An electrical circuit is provided (FIG. 4) for controlling operation of the machine. For this purpose, the circuit includes customary power leads 119 adapted to be connected with a suitable source of electrical current. Directly connected in this circuit are the pump motor and the blower and chain drive motor 111, so that when a master control switch 120 is closed the document and copy sheet transport systems and the blower run continuously and the liquid toner 84 is in constant circulation for optimum toner distribution throughout the liquid vehicle and for continuous replenishment of the toner supply in the development tray. Conveniently the master switch is mounted on the front of the cabinet (FIG. 1) for suitable on and off manipulation.

Operation of the copy sheet feed drive motor 65 is under control of the document to be copied and of the successive copy sheets and the copy sheets control operation of the lamp 41 and the charging device 74. For this purpose, the lamp 41, the feed motor 65 and a power pack 121 for the corona discharge device are connected in the electrical power supply circuit under the control of various trip or micro switches including a normally open switch 122 which is mounted on or adjacent to the document guide plate 22 between the document transport rollers 21 and 25 and has a trip arm 123 disposed in the path of the in-travelling document when it enters the flow or guide path between the plates 22 and 23. Tripping of the actuator 123 by the document, closes the switch 122 and thereby closes the energizing circuit through the feed motor 65 whereby one of thecopy sheets 59 is fed into the copy sheet transport system and actuates a two-way control switch 124 (FIGS. 2 and 4) having a trip arm 125 disposed in the path of the copy sheet between the transport rollers 72, 73 and the corona charging device 74. Thisbreaks the circuit through the feed motor 65 and closes a circuit to energize a relay 127 closing normally open switch contacts 128 and completing an energizing circuit through the lamp 41 and the corona discharge power pack 121. The switch 124 remains under the control of the copy sheet until the trailing end of the copy sheet leaves the transport rollers 80 and 81, by provision of a second actuator 129 extending into the path of the sheet on the exit side of the transport rollers 80 and 81 and just above the lead-in lip 83 of the developer tray.

Promptly upon release of the switch actuator 129 from the charged copy sheet, the switch 124 automatically returns to its feed motor circuit closing condition and the feed motor 65 is energized to feed the next succeeding copy sheet from the magazine into the guide throat 71. At the exit from the guide throat and immediately before the copy sheet transport rollers '72 and 73 a trip arm or 131 is tripped by the leading edge of the newly fed copy sheet and opens the switch 131 to open the feed motor circuit and deactivate this motor until the shunt around the switch 131 is again closed by closing of the control switch 122 by a document to be carried. For synchronization the distance from the tripping position of the trip arm 123 of the 130 of the control switch 131 and the near edge of the exposure aperture' 53. Thereby,

automatic synchronizaand corresponding copy sheets is attained for high speed operation. In practice virtually as soon as a document to be copied is returned through the exit 38, the finished copy is delivered into the receiving hopper in the lower front of the machine and in a sufliciently dry condition to be handled immediately.

In order to accommodate various illumination intensity requirements for different types of document copy, a shutter 132 is pivotally mountedadjacent to the scanning mirror 43 and is operable from the front of the machine oy means of a lever 133 to modulate the intensity of the image reflected onto the mirror from the scanning aperture 29.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

We claim as our invention:

1. An electrophotographic machine comprising a housing having an upper front entry opening receptive of a document to be copied,

a document exit opening immediately below said entry opening,

means defining a document path from said entry opening to said exit opening and including document transporting means and a document scanning aperture,

an exposure lamp and reflector mounted in the housing adjacently below said exit opening and trained toward said scanning aperture,

a reiiecting mirror below said reflector and lamp and scanning each document traversing said scanning aperture,

a projection tunnel having projection optics therein and leading from said mirror generally upwardly and rearwardly and terminating in an exposure aperture,

a copy paper supply magazine in the top of said housing,

a paper charging corona discharge device between said magazine and said exposure aperture,

means operative to feed paper from the magazine through the corona discharge device and then through said exposure aperture,

a liquid toner receptacle below said exposure aperture receptive of the exposed paper after it leaves the exposure aperture,

squeeze rollers engageable with the developed copy paper on leaving the bath,

a copy receptacle accessible from the front of the housing and located below said morror,

and means defining a copy discharge chute leading forwardly from said squeeze rollers to said copy receptacle and including overlying downwardly facing shield means along the bottom of the light tunnel defining the upper side of the chute.

2. A machine as defined in claim 1, in which said shield means include longitudinal downwardly projecting spacer means.

3. An electrophotographic machine comprising a housing having an upper front entry opening receptive of a document to be copied,

a document exit opening immediately below said entry opening,

means defining a document path from said entry opening to said exit opening and including document transporting means and a document scanning aperture,

an exposure lamp and reflector mounted in the housing adjacently below said exit opening and trained toward said scanning aperture,

a reflecting mirror below said reflector and lamp and scanning each document traversing said scanning aperture,

a light tunnel leading from said mirror generally upwardly and rearwardly and terminating in an exposure aperture,

a copy paper supplymagazine in the top of said housa paper charging corona discharge device between said magazine and said exposure aperture,

means operative to feed paper from the magazine through the corona discharge device and then through said exposure aperture,

a liquid toner receptacle below said exposure aperture receptive of the exposed paper after it leaves the exposure aperture,

squeeze rollers engageable with the developed copy paper on leaving the bath,

a copy receptacle accessible from the front of the housing and located below said mirror,

and means providing movement of air under the copy and effecting propulsion of the copy into the copy receptacle on leaving the squeeze rollers.

4. A machine as defined in claim 3, in which said transporting means include transport rollers, said movement of air being effected by a fan and a motor operating the fan, and means connected with said motor for driving said transport rollers and said squeeze rollers.

5. An electrophotographic machine comprising a housing hvaing an upper front entry opening receptive of a document to be copied,

a document exit opening immediately below said entry opening,

means defining a document path from said entry opening to said exit opening and including document transporting means and a document scanning aperture,

an exposure lamp and reflector mounted in the housing adjacently below said exit opening Iand trained toward said scanning aperture,

a reflecting mirror below said reflector and lamp and scanning each document traversing said scanningv aperture,

a light tunnel leading from said mirror rearwardly and terminating in an exposure aperture,

a copy paper supply magazine in the top of said houslng:

a paper charging corona discharge device between said magazine and said exposure aperture,

means operative to feed paper from the magazine through the corona discharge Idevice and then through said exposure aperture,

a liquid toner receptacle below said exposure aperture receptive of the exposed paper after it leaves the -exposure aperture,

squeeze rollers engageable with the developed copy paper on leaving the bath and directing the copy paper generally forwardly,

a copy receptacle accessible from the front of the housing 'and located below said mirror,

a forwardly and `downwardly inclined chute leading from said rollers to said receptacle,

and means circulating cooling air over said lamp to remove heat therefrom Iand then directing the heated air onto the underside of the copy paper as it leaves said rollers and moves down said chute to dry the copy as it travels to said receptacle. i

6. An electrophotographic machine comprising a housing having an upper front entry opening receptive of a document to be copied,

a document exit opening immediately below said entry opening,

means defining a document path from said entry opening to said exit opening and including document transporting means and a document scanning aperture,

an exposure lamp and reflector mounted in the housing adjacently below said exit opening and trained toward said scanning aperture, a reflecting mirror below said reflector and lamp and scanning each document traversing said scanning aperture,

a light tunnel leading from said mirror rearwardly and terminating in an exposure aperture,

a copy paper supply magazine in the top of said housing,

a paper charging corona discharge device between said magazine and said exposure aperture1 means operative to feed paper from the magazine through the corona discharge device and then through said exposure aperture,

a liquid toner receptacle below said exposure aperture receptive of the exposed paper after it leaves the exposure aperture,

squeeze rollers engageable with the developed copy paper on leaving the bath,

a copy receptacle accessible from the front of the housing and located below said mirror,

paper guide means leading downwardly and forwardly from said squeeze rollers to said receptacle,

and means operative to remove heated air from the area of said lamp and constructed to direct the heated air under the copy as it leaves said rollers and while said guide means guides it toward said receptacle whereby to provide both a transporting air cushion for floating the copy from the rollers to the receptacle, and copy drying heated air circulation.

7. An electrophotographic copying machine comprising,

means defining an exposure aperture,

means operative to transport `a document original through said exposure aperture,

means dening an electrostatically sensitive copy sheet magazine,

means for feeding copy sheets from said magazine land including a drive motor,

a sheet charging corona discharge device,

means defining an exposure aperture,

means for transporting a copy sheet fed from said magazine first through the corona discharge device and then through said exposure aperture,

means for driving both of said transporting means,

means for scanning the document original n passing through the scanning aperture and directing the image thereof photographically through said exposure aperture,

and electrical control circuitry for said feed motor comprising a normally open rst control switch closed by the document original for Iactivating the motor to feed a copy sheet from the magazine to said copy sheet transporting means concurrently with transportaion of the document to the scanning aperture and a second control switch having a normally closed phase opened by said copy sheet after the copy sheet has left the feed means to stop the motor and then closing when released from the copy sheet a third normally closed switch disposed along the path of land opened by the copy sheet in movement from said magazine to said copy sheet transporting means, said third switch closing after the trailing end of the copy sheet reaches said copy sheet transporting means for closing the circuit to the motor, advance of a succeeding copy sheet from the magazine being stopped when its leading edge closely approaches said copy sheet transporting means and opens said third switch to deactive the motor, and a shunt around said third switch for activation of said motor when a succeeding document original closes said first switch.

S. In an electrophotographic copy making machine,

means defining a scanning aperture,

means for transporting a document original through the scanning aperture,

means defining an exposure aperture,

means for transporting a copy sheet through said exposure aperture,

an electrostatic charging device in the path of movement of the copy sheet ahead of said exposure aperture,

means defining a copy sheet magazine,

means for feeding copy sheets from the magazine to said copy sheet transporting means and including a drive motor,

scanning aperture illuminating lamp means,

an optical system for scanning the illuminated document passing through said scanning aperture 'and directing the image of the document into said exposure aperture onto a charged copy sheet passing therethrough,

means for driving both of said transporting means in unison,

and electrical control circuitry for said feed motor and said illuminating lamp and said charging means including:

a normally open first control switch closed by the document original for activating the motor to feed a copy sheet from the magazine to said copy sheet transporting means concurrently With transportation of the document to the scanning aperture, a second control switch having a normally closed phase opened by said copy sheet after the copy sheet has left the feed means to stop the motor and then closing when released from the copy sheet, a third normally closed switch disposed along the path of and opened by the copy sheet in movement from said magazine to said copy sheet transporting means, said third switch closing after the trailing end of the copy sheet reaches said copy sheet transporting means for closing the circuit to the motor, advance of a succeeding copy sheet from the magazine being stopped when its leading edge closely approaches said copy sheet transporting means and opens said third switch to deactivate the motor, and a shunt around said third switch for activation of said motor when a succeeding document original closes said first switch, said second switch having a normally open phase closed by said copy sheet in movement through said copy sheet feeding means to energize said electrostatic charging device and said lamp means.

9. In a copy making machine of the character described:

a housing having means in the front upper portion thereof for receiving, transporting and scanning a document to be copied;

means in the rear of the housing for transporting and electrostatically charging a photoelectrically sensitive copy sheet;

means for exposing the copy sheet to lan image of the document;

means in the lower rear of the housing for developing the exposed copy sheet in liquid toner;

means between said first mentioned means and the bottom of the housing defining a discharge passage open at the front of the machine;

and means for transporting the sheet from the developing means through said passage comprising downwardly and forwardly directed guide means and means associated therewith for creating Vair circulation toward the front of the machine in said passage, and providing an anti-friction air layer under the sheet to iioat the sheet toward the open front end of said passage.

10. A machine as defined in claim 9, in which said guide means comprise a guide plate leading from the developing means toward the front of the discharge passage and over which said sheet travels in said passage.

11.' A machine as dened in claim 9, in which said guide means comprise a guide plate over which said sheet travels in said passage and which plate has louvers therein, Vand said means for creating air circulation cornprise a squirrel cage blower operatively mounted under said plate.

12. A machine as defined in claim 9, in which said means for exposing the copy sheet to an image of the document include a light tunnel in the lower portion of the housing having a downwardly facing wall overlying and providing the upper side of said discharge passage, and said guide means comprise a plate spaced below said lower wall of the tunnel and dening therewith a chute leading from said means for developing the exposed copy sheet.

13. An electrophotographic machine comprising a housing having an upper front entry opening receptive f a document to be copied,

a document exit opening immediately below said entry opening,

means defining a document path from said entry opening to said exit opening and including document transporting means and a document scanning aperture,

an exposure lamp and reflector mounted in the housing adjacently below said exit opening and trained toward said scanning aperture,

a reecting mirror below said reflector and lamp and scanning each document traversing said scanning aperture,

a projection tunnel having projection optics therein and leading from said mirror generally upwardly and rearwardly and terminating -in an exposure aperture,

a copy paper supply magazine in the top of said housing,

a paper'charging corona discharge device between said magazine and said exposure aperture,

means operative to feed paper from the magazine through the corona discharge device and then through said exposure aperture,

a liquid toner receptacle below said exposure aperture receptive of the exposed paper 'after it leaves the exposure aperture,

squeeze rollers engageable with the developed copy paper on leaving the bath,

a copy rceptacle accessible from the front of the housing and located below said rnirror,

said means defining a document path and the document transporting means including two spaced sets of document engaging and moving rollers1 one of which sets is aligned with said entry and exit openings and the other of which is located in a position downwardly and inwardly relative to said one set,

document guide members mounted between said sets of rollers to guide `documents therebetween,

and a semi-cylindrical guide member mounted in association with said second set of rollers and operative to reverse the direction of movement of the documents moved by the second set of rollers, said scanning aperture facing toward said reflector.

References Cited UNITED STATES PATENTS 2,751,814 6/ 1956 Limberger 88-24 2,771,816 11/1956 Pfat 88-24 3,005,389 10/1961 Limberger 95-1.7 3,245,330 4/ 1966 Okishima 95-1.7 3,272,100 9/1966 Teutsch 95-1.7

JOHN M. HORAN, Primary Exrrrrrrner. 

1. AN ELECTROPHOTOGRAPHIC MACHINE COMPRISING A HOUSING HAVING AN UPPER FRONT ENTRY OPENING RECEPTIVE OF A DOCUMENT TO BE COPIED, A DOCUMENT EXIT OPENING IMMEDIATELY BELOW SAID ENTRY OPENING, MEANS DEFINING A DOCUMENT PATH FROM SAID ENTRY OPENING TO SAID EXIT OPENING AND INCLUDING DOCUMENT TRANSPORTING MEANS AND A DOCUMENT SCANNING APERTURE, AN EXPOSURE LAMP AND REFLECTOR MOUNTED IN THE HOUSING ADJACENTLY BELOW SAID EXIT OPENING AND TRAINED TOWARD SAID SCANNING APERTURE, A REFLECTING MIRROR BELOW SAID REFLECTOR AND LAMP AND SCANNING EACH DOCUMENT TRAVERSING SAID SCANNING APERTURE, A PROJECTION TUNNEL HAVING PROJECTION OPTICS THEREIN AND LEADING FROM SAID MIRROR GENERALLY UPWARDLY AND REARWARDLY AND TERMINATING IN AN EXPOSURE APERTURE, A COPY PAPER SUPPLY MAGAZINE IN THE TOP OF SAID HOUSING, A PAPER CHARGING CORONA DISCHARGE DEVICE BETWEEN SAID MAGAZINE AND SAID EXPOSURE APERTURE, MEANS OPERATIVE TO FEED PAPER FROM THE MAGAZINE THROUGH THE CORONA DISCHARGE DEVICE AND THEN THROUGH SAID EXPOSURE APERTURE, A LIQUID TONER RECEPTACLE BELOW SAID EXPOSURE APERTURE RECEPTIVE OF THE EXPOSED PAPER AFTER IT LEAVES THE EXPOSURE APERTURE, SQUEEZE ROLLERS ENGAGEABLE WITH THE DEVELOPED COPY PAPER ON LEAVING THE BATH, A COPY RECEPTACLE ACCESSIBLE FROM THE FRONT OF THE HOUSING AND LOCATED BELOW SAID MIRROR, AND MEANS DEFINING A COPY DISCHARGE CHUTE LEADING FORWARDLY FROM SAID SQUEEZE ROLLERS TO SAID COPY RECEPTACLE AND INCLUDING OVERLYING DOWNWARDLY FACING SHIELD MEANS ALONG THE BOTTOM OF THE LIGHT TUNNEL DEFINING THE UPPER SIDE OF THE CHUTE. 